Preparing iron oxid for use in blast-furnaces.



PEN) S YLVANIA.

PREPARING IRON OXiD FOR USE 5N BLAST'FUFZNACES- Specification of LettersPatent.

Patented Nov. 14, 1905.

Application filed November 4:, 1904. Renewed August 23,1905. Serial No.275,510.

To all whom it may concern.-

Be it known that I, [lTLEY- vVEDGl-J, a citizen of the United more,Pennsylvania, have invented certain Improvements in Preparing lroirOxidfor Use in lilast-lr nrnaces, of which the followin i is aspecification.

The OllJUClI of my 1nvent1on is toprepare for use in ablast-furnacerelatively fine particles of oxid of iron, such as the red hematiteores, and the cinder resulting from the desulfurization of iron pyritesin the manufacture of sulfuric acid. These relatively fine particles ofoxid of iron are not available for use in the blast-furnace, first,because of their tendency to pack and render the furnace charge toodense for the passage of the blast therethrough, and, secondly, becausewhen a high-pressure blast used they are liable to be carried offthereby and deposited in the fines of the furnace. oxids can be renderedavailable for blast-furnace use by combination with Portland cement, (orits principal constituents when properly pulverized) the cement beingmixed with the finely-divided iron oxid and the mixture then subjectedto a proper degree of heat.

Portland cement is usually made from marl and clay, or chalk and clay,or argillaceoui limestone by grinding the crude materials, mixing thesame, calcining them to a clinker, and grinding the latter. its usualcompost tion is followsqsilica, about twenty-two percent. alumina, abouteight per cent; iron oxid. about three per cent; magnesia, about two percent; lime, about sixty-two per cent; sulfuric acid, about 1.75 percent. The various elements are often considerably varied; but in allcases the mixtures are regulated or the crude material is selected withreference to its clinkering or attaining the point of incipient fusionat about a temperature of twenty-four hundred (QAOO degrees Fahrenheit.As this temperature is just below the fusing-point of iron oxid, l havefound that the material is especially adapted for effecting theagglomeration of theiron oxid into lumps or nodules, and such result cantherefore be economically and practically secured in this way. Themixture should contain about three (3) per cent. of the cement andshould preferably be subjected to agitation during the time it is beingheated, the most convenient method of accomplishingsuch agitation beingto feed the mixtliire through a rotating kiln of suitable length whoseaxis is slightly lllCllDBt l have found that such finely-divided l l v il 4 i p I l l l l i i l i l l i in respect to the horizontal, the kilnbeing j heated externally or internally or both. States, and a residentof i-irdl Instead of using cement l ctlect use the flue-dust whichaccumulates in ccmentmrning furnaces. such flue-dust being about two (2)per cent. higher in silica than the cement itself and being somewhatmore readily fusible and besides not possessing as high a commercialvalue as the'cement itself. Obviously also the use of the crude materialfrom which cement is made will give the same results as the use of thefinished cement, since the fusing-point of the material is substantiallythe same both before and after calcination. Similar results can also besecured by a mixture having substantially the same constituents as thecement or cement material for instance, by a mixture of pure limestonewith silicious clay in about the proportions in which these substancesoccur in cement. Hence in the term cement as used in the claims Iinclude suchcenicnt materials either before or after calcination.

It should be understood that in carrying out my invention I do not relyupon the cement qualities of the material, but take advantage of thefact that it has a fusing-point close to that of the iron oxid. Hencematerial ofchemical constitution and fusing qualities substantially thesame as cement may be employed in carrying out my invention even if itscement qualities are poor or lacking, my invention aiming to utilize anentirely-different function from that for which cement is commerciallyemployed.

Having thus described my invention, I claim and desire to secure byLetters Patent 1. The mode herein described of preparing relatively fineparticles of iron oxid for use in a blast-furnace, said mode consistingin mixing said particles with Portland cement and subjecting the mixtureto such a degree of heat. as will effect fusion of said cement,substantially as specified.

2. The mode herein described of preparing relativelyline particles ofiron oxid for use in a blast-furnace, said mode consisting of mixingsaid particles with Portland cement, and then subjecting the mixturesimultaneously to agitation and to such a degree of heat as will effectfusion of the cement, substantially as specified.

3. The mode herein described of preparing relatively fine particles ofiron oxid for use in a blast-furnace, said mode consisting in mixingsaid particles with tine-dust of Portlandmay with good and subjectingthe Y to such a de mixtuz'e ta 3e 9% heatas will effect smimmmlallyspec;- fi ed.

see sf st, sub

heat as will efiect fusion 5 tially as specified.

i In testim 1' W 1 2 eof 111% e signed nag/name to ch15 ape-cificatmn ind e 4%:

4. 16 new harem C13SCTlbCi 0r preparmg scribing witnessas, "9L finepartlcies 0t 1mm 0221c. 1'01 use 1 I send made can ting of mix. A fiwadusi of Portlandiurnmms, and t- "Witn' -ses:

m "mm WDMINELL CHARLES. E. MILLER.

hen subjecting iultaneously t0 aglmtzon and y I garesence of two sub-

